Environment Canada has issued a heat warning for Barrie and all of Southern Ontario.
The national forecaster says the first heat event of the season starts today.
Temperatures are expected to be near 31 degrees Sunday and near 32 Monday with overnight lows near 21 degrees, providing little relief from the heat during this timeframe.
We can expect a mix of sun and cloud today. 30 percent chance of afternoon showers and risk of a thunderstorm. Wind gusting up to 40 km/h this morning. High 31. Humidex 36.
EC says it's possible these heat conditions will persist into Tuesday. Temperatures will fall below heat warning criteria by the middle of this week.
The heat risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.
Watch for the effects of heat illness including swelling, fainting, rash, cramps and heat stroke.
Drink plenty of water even before you feel thirsty and stay in a cool place.
Seek a cool place such as a tree-shaded area, swimming pool, shower or bath, or air-conditioned spot like a public building.
Never leave people or pets inside a parked vehicle.